Proper names and (geographical and ethnic) proper nouns which appear in 'Rozmyslanie przemyskie' (The Przemysl Meditation), a medieval religious text, are mostly of Biblical origin and were borrowed into Polish from Latin manuscripts. This paper discusses the adaptation processes that such nouns undergo in Polish texts, their origins, frequency of use, as well as the principles of their interpretation. The Appendix lists selected proper names and proper nouns in alphabetical order together with comments on their etymology and revisions of incorrect interpretations.